Base support doesn't fade. It just gets pissy for awhile.
Tell that to Jimmy Carter.
Jimmy Carter,
You still won your 40% base. You didn't win any swing voters.
Thanks,
King
How did Mondale get 37,577,352 to Carter's 35,480,115? That's about two million base votes that Carter lost from people supporting Anderson or not voting at all, not to mention all of the "Reagan Democrats" that were lost too.
But I am not going to disagree with your overall sentiment. You're absolutely right that the vast majority of the base will still vote for their guy. However, it is not written in stone that all of Obama's base is going to show up no matter what to support him.